The issue is that as an employee you don't have that choice. Somebody else makes those decisions for you, you're just along for the ride.
Everything else follows from that. The fact that employees get any shares at all is just a way to get better employees so that the company does well. Only employees of unicorns have any chance of getting wealthy from stock, and you're unlikely to be an early employee of a unicorn.
It's better to view the situation in absolute terms rather than relative terms. Instead of comparing the outcomes of founders/VCs vs employees, compare an employee of a startup to an employee of non-startups. At not-startups, the working environment is very different. Some people enjoy that, some prefer the opposite. Also, getting +$100k (or +$50k, or even just +$10k) is still nice, even if the founders and VCs get 800x more.
The only part I have serious concerns about is the fact that you can end up underwater when it comes time to exercise your options, i.e. your tax bill outweighs whatever profits you'd see. I don't know exactly how this situation arises, but it happened to a friend. It was something like: he could have exercised his shares and gotten several hundred thousand, but he would've needed to pay about $100k in taxes beforehand. Since he didn't have that money, he couldn't exercise the options.
I might be wrong about the specifics, but there are situations similar to that, and it's pretty unnerving knowing that you can jump into a situation where your +$100k somehow turns into -$50k.
But even your example wasn't that. Your examples was -100k and +300k (or more), but offset by time slightly. That's still a very large net positive, just gated by a period of net negative.
I suspect there are some details that you are missing as to the situation of your friend. I know little about investment vehicles, but I've filed taxes at one point and paid them at a later point many times. For income taxes the rules for this are clear, and the amount you pay in fees and interest is also very clear. For some investment vehicle, I would bet if there's some taxes that need to be paid prior they have automated processes set up to pay them for you and take the amount out of the later payout, for a fee. If not, I can't imagine getting a short term loan for that would be too hard, even if you have to use private money (a real investor, or even just a friend).
As someone who has been exactly there, this doesn't compensate for the lower salaries that are de rigeur in startups. Not to mention being an absolute insult compared to the employee's degree of contribution to the resulting event.
"Better than nothing, or being underwater" is pretty thin gruel in practice.
Does this mean that stock options are not a measure of risk taken by the employee into the company?
You mean the stock options are just like cash? I didn't think so. The employee is invited to take risks but without the protections.
I feel like at least a phone call to a bank would be in order at that point. If it's that simple, surely some sort of mutually agreeable loan could be worked out.
Surely if they're private shares that can't be sold the extrinsic value is zero, the private share value for tax purposes is no greater than the value of the option?
Define wealthy.
I have done quite well (not FU, 3-comma money, of course, but solidly 2-comma) from equity as an employee. In my current company, I joined a few months after the Series A (so nowhere near "early"), stayed through the IPO and many years of growth past that.
We were never a unicorn.
Amazon, Facebook, and Google are regularly turning SWEs into millionaires and a substantial part of that is from equity. Microsoft also had a good decade and a half of doing that. Netflix probably does as well. (OK, Facebook was a unicorn; the others probably weren't ever called that, though it may have fit.)
The point in the GP post that I was expanding upon,
> It's zero net gain at the point of dilution.
is focussing on the wrong instant in time.
You should be calculating the effect of the dilution on your exit event, when your equity actually becomes exchangeable for money.